1. Field of the Invention
The present invention pertains generally to medical instrumentation, and more specifically to a device for moving the uterus (along with adnexa) to different positions for better visualization and surgical access.
2. State of the Art
Some type of uterine manipulator is currently deemed essential by practitioners for all laparoscopies involving the female pelvic organs (uterus, tubes, ovaries) when a uterus is present, as surgery without a uterine manipulator is more dangerous and can be more time consuming. Exemplary laparoscopies in which a uterine manipulator has substantial utility include: tubal ligations; diagnostic laparoscopies for evaluating pelvic pain and infertility; treatment of endometriosis, removal of pelvic scars (adhesions) involving the uterus, fallopian tubes and ovaries; treatment of ectopic pregnancy; removal of uterine fibroids; removal of ovarian cysts; removal of ovaries; tubal repair; laparoscopic hysterectomy, laparoscopic repair of pelvic bowel or bladder; sampling of pelvic lymph nodes; "tying up" the bladder to prevent urine loss; and biopsy of pelvic masses.
Uterine manipulators are also employed as conduits for the delivery of dye into the uterus when the physician wishes to obtain a picture of the uterus (hysterosalpingogram), and has become an important feature of manipulators. However, due to poor design, dye leakage through the cervix is very common, which may cause imaging problems as well as interfering with the procedure.
Most state of the art manipulators are merely rigid instruments which attach in a fixed manner to the uterus and protrude from the vagina. The instrument is typically held in place by sharp hooks embedded in the cervix, such as with a tenaculum. A typical example of such prior art devices is the Majoli Uterine Manipulator/Injector, sold by Cook Urological, Inc. of Spencer, Ind. (see FIG. 1). The handle of the instrument is grasped outside the vagina, and uterine manipulation is effected by applying torque to the rigid handle of the device at a point some distance from the organ. The uterus typically may be elevated only 45.degree. from the vaginal axis, or lowered 10.degree.-15.degree.. The capability for movement to the right or left is minimal, and pelvic tissues and organs are unnecessarily stressed by application of excessive torque. Exposure of the vital regions of the pelvis is difficult, and surgery with such instruments is often suboptimal or even unsafe. Further, such devices and methods routinely require an extra staff member to maintain the instrument in the correct position to perform a procedure. In some cases this is very cumbersome, and obviously adds time and cost to the procedure.
One of the most significant complications of the aforementioned type of manipulator is tearing of the cervix with the tenaculum as the manipulator is adjusted and positioned, causing persistent and occasionally extensive bleeding. Such problems occur most often with inexperienced or inadequately trained personnel. The end result is longer operating room time with associated expense, as well as longer patient recovery and concern caused to the patient due to vaginal bleeding.
Another potential complication is uterine perforation resulting from excessive force being exerted by the physician when trying to place the manipulator into the uterus or during attempted manipulation of the uterus for better visualization. While infrequent, such an occurrence may convert the procedure from a laparoscopy to a laparotomy.
In an attempt to avoid the above problems, a class of manipulators has been developed which use a balloon inflated at the distal end of the instrument after the instrument has been inserted to perform the function of the tenaculum. Examples are the Harris Uterine Manipulator Injector (HUMI) disclosed in U.S. Pat. No. 4,430,076, and similar devices marketed as the Zinnanti Uterine Manipulator Injector (ZUMI) and the Kronner manipulator. The HUMI was the first plastic, disposable manipulator. The HUMI uses an intrauterine balloon and external spring and stop at the cervical os. Another device of this type, which uses two balloons mounted on a long, stiff metal rod, one inside and one outside of the uterus, is marketed by C.R. Bard, Inc. of Tewksbury, Mass.
A major drawback with this class of devices is the lack of good manipulatory control. Without a pivot point at the cervical opening, these instrument are severely limited in their effective range of motion, in part due to the shape of the device itself and in part due to the configuration of such devices, which limits manipulation due to contact with the table on which the patient is placed or contact between the patient and the instrument. The cannula is not rigid enough for effective manipulation, and side-to-side motion is very difficult if not impossible to effect due to inadequate rigidity, lack of an ergonomic handle and the shape of the device. FIGS. 2A and 2B, illustrating the use of a HUMI-type manipulator inserted in a patient uterus 60, clearly illustrate these shortcomings.
A more preferable approach to uterine manipulation employs an instrument having a rotatable hook (tip) or finger mounted at a pivot point proximate the cervical os, as provided by the Valtchev Uterine Mobilizer, one version of which is disclosed in U.S. Pat. No. 4,022,208. Such devices allow much easier and more effective manipulation of the uterus over a somewhat wider range of motion, although such is still severely limited due to the linkage employed to rotate the hook. However, the Valtchev manipulator persists with the use of a tenaculum to grasp the cervix (although the risk of uterine perforation is significantly reduced by the effective manipulation capability provided by the pivot location's proximity to the os). Furthermore, the instrument's cost and complexity constitute a serious impediment to widespread use, and the reusable nature of the device causes cleaning problems due to the use of a long spring and cannula and the presence of numerous crevices on the surface of the device.
Another, more recent development in uterine manipulators is disclosed in U.S. Pat. No. 5,237,985. The so-called "uterine retractor" of the '985 patent is depicted in several different forms, one with a pistol-grip arrangement at the proximal end of an elongated rod and an articulated mechanical linkage to cause rotation of a retractor finger pivoted at the distal end, and a second with a rotatable handle or knob at the proximal end of an elongated rod driving a retractor finger on a drum pivoted at the distal end through one or more wires secured at one end to the handle and at the other end to the drum. These devices have a fairly large number of parts, and in reusable form as disclosed are costly, complex and present the same contamination and cleaning problems as the Valtchev device. Moreover, the rotational range of motion about the pivot point is constrained to about 115.degree. due to the nature of the drive linkages employed between the proximal and distal ends of the elongated rods to pivot the retractor finger, and substantial retroversion of the finger is not achievable. Due to the design of the drive linkage, the force applied by the user to rotate the handle or knob is unevenly transmitted to the drum over the rotational extent of movement of the retractor finger. The fact that the drive linkage "pushes" as well as pulls the drive wires secured to the drum and to the handle or knob requires the use of spacers or guides and limit stops to prevent binding and kinking of the wires and collapse of the drive linkage, particularly at its rotational extremes. In addition, the device of the '985 patent employs a spring-loaded ball or plunger biased into a plurality of sockets positioned at a common radius about the rotational center of the handle or knob to produce a "ratcheting" effect to provide the user with an indication of rotational movement of the drum. However, the holding force of the foregoing assembly is insufficient to maintain the uterus in an elevated position, thus requiring an extra staff member to grasp and immobilize the handle or knob to maintain the uterus in any unnatural position.
Also disclosed in the '985 patent are several embodiments of retractor fingers for use in association with the manipulator at the distal end thereof, several of the embodiments including a lumen-fed balloon, and optionally a second lumen for hydrotubation. In one embodiment, a third lumen houses a rigid structural member within the center of the retractor finger. As each lumen must be sufficiently large to perform its intended function and an adequate membrane must surround each lumen, the diameter of the tri-lumen stem is sufficient to require significant dilation of most patients. The result is trauma to the patient and added time and expense to the surgical procedure.
Another recently-developed uterine manipulator is the Gregersen U-Elevator offered by Karl Storz-Endoskope, which comprises a U-shaped rod having a cone for insertion into the uterus at one end and a weighted handle at the other end, a lumen for dye injection running from the handle and through the rod and the cone. The device permits the patient to lie in a normal position on her back, and the handle may be grasped by the surgeon to manipulate the uterus. However, the U-Elevator device is expensive and suffers from the inability to manipulate a tip assembly (in this case the cone) independently of the entire device, and the severe U-shape of the device limits its range of movement.
Although progress has been made in the art as noted above, all existing uterine manipulators known to the inventors herein possess significant disadvantages and limitations. With the increasing pressure for cost containment in medical treatment and the increasing popularity of laparoscopic gynecological procedures moving to outpatient clinics and GYN offices, a cost-effective uterine manipulator having enhanced manipulation capability and ease of use would be very attractive to the medical profession.